Cellular type robot apparatus

ABSTRACT

This invention relates to a cellular type robot apparatus consisting of a plurality of robot cells each having intelligence, wherein each robot cell controls its own operation on the basis of information exchange with adjacent robot cells. The operations of the robot cells are as a whole coordinated, and each robot cell can be controlled without the necessity of change of hard- and soft-wares even when one or more of the robot cells are out of order or when the robot needs to be expanded. Each robot cell can be provided so that the robot can be increased or decreased in a building block arrangement. More definitely, each robot cell has arms corresponding to hands and feet, and is able to control its own operation. As the robot cells are connected and combined through transmission routes so as to be able to exchange information, they can operate cooperatively as a group to perform a manpulative action. The operation of the group of robot cells is designed also to constitute the shape of a predetermined pattern besides the operations of entwining an object, and gripping and moving the object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method of constituting a robot consisting ofa plurality of robot cells that can operate independently, are connectedto one another and move coordinately due to information exchange betweenthem to perform a manipulative action. The present invention relatesalso to an apparatus for realizing such a robot.

2. Description of the Prior Art

In a conventional robot, the function of the robot is distributed toeach portion of the robot, the data from each distributed portion isgathered by a central processing unit, and the central processing unitin turn operates each distributed portion by giving an instructionthereto.

Therefore, it has been necessary to produce a specific apparatus foreach distributed portion, and when the central unit is out of order oroperates abnormally, it is likely that the robot as a whole undergoes abreakdown or operates dangerously. Moreover, the robot must be changedin accordance with the size of an object which is to be dealt with bythe robot. The freedom of operation of the robot, which is determined bythe number of a joints of arm, is low, so that the robot can not operateflexibly and continuously, and its response is low.

SUMMARY OF THE INVENTION

The present invention is directed to provision of a robot apparatuswhich can be assembled by merely combining in various ways a pluralityof autonomous robots cells, that can operate independently with oneanother, so as to eliminate the necessity of a central unit, but has theadvantage that it does not undergo system breakdown when one or more ofthe robot cells is or are out of order, and has a high response becausethe individual robot cells react simultaneously, can perform flexibleoperations, and because they exchange information between them andcoordinate with one another to control their operations by themselves.

Each robot cells includes first means for detecting its own operatingcondition, second means for detecting the operation of the other robotcells, means for setting the object of its own operation on the basis ofthe conditions detected by the first and second means, and means forcontrolling its own operation in accordance with the object of theoverall operation.

The cellular type robot apparatus of the invention consists of at leastone group of robot cells of the type described above that are connectedwith one another, and may include third means for setting the object ofthe overall operation of the group of robot cells.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show the overall construction of the system of the presentinvention;

FIG. 3 shows an arm driving device of one embodiment of the presentinvention;

FIG. 4 shows a first embodiment of the cell of the present invention;

FIG. 5 shows one embodiment of a controller inside the cell of thepresent invention;

FIGS. 6 through 8 show the concepts of the operation of a group of robotcells of the present invention;

FIG. 9 shows the construction of controller inside the cell of thepresent invention;

FIG. 10 shows the concept of the motion of the arm of the cellular robotof one embodiment of the present invention; and

FIGS. 11 through 13 show the operation due to the relation between agroup of cells of the present invention and an object.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows the overall construction of the system. The robot isconstructed as a whole by a plurality of robot cells 11, 12, . . . , andthese cells are connected to adjacent robot cells by arms 111, 121, . .. 112, 212, . . . , . In FIG. 1, the robot cells are shown disposed on atwo-dimensional plane, and each cells 11, 12, . . . is connected to theadjacent robot cells on the lateral and longitudinal axes by the lateralarms 111, 121, . . . and the longitudinal arms 112, 122, . . . ,respectively.

The structure of each robot is changed as depicted in FIG. 2 when thelengths of the respective lateral and longitudinal arms are adjusted. Anarm driver such as shown in FIG. 3 and a controller for driving the armsuch as shown in FIG. 5 are incorporated in each robot cell. Eachcontroller is connected to the controllers of the adjacent robots by atransmission medium so as to exchange information. Since the informationis exchanged between the adjacent robot cells, each cell operatescooperatively.

FIG. 3 shows the arm driver of each robot cell. One of the arms is anactive arm 2211 equipped with a servo motor 2215 and a gear 2213, whilethe other is a negative arm 2212 equipped with a guide 2214 for the gear2213. These active and negative arms 2211 and 2212 are connected to therobot cell main body by shafts 2216 and 2217, respectively. Unless theseshafts are locked, the arms can freely change their directions. The armlength can also be adjusted freely by rotating the gear 2213 using theservo motor 2215.

As shown in FIG. 4, the active arms 2211, 2221 and the negative arms1222 and 2112 are disposed inside the robot cell in the lateral andtransverse directions, respectively, and are connected to the four robotcells adjacent thereto. The robot cell can move freely in the lateraland longitudinal directions by the active arms 2211 and 2221. In theactive arms, too, the gear can be freely rotated (or be brought into thefree state) by cutting off the power of the servo motor 2215. The armlength can be fixed (or locked) by fixing the gear 2213. A longitudinalarm fixing connector 1232 is disposed so as to integrally connect theactive/negative arms 1222, 2221 of the longitudinal axis and to preventthem from rotating independently.

The internal construction of the robot cell is such as shown in FIG. 5.The controller 22011 calculates the moving quantity of the arm on thebasis of information applied thereto from sensors 22014, 22024 forrecognizing an object existing in the longitudinal and lateraldirections, for example, from an angle sensor for measuring the anglebetween the negative longitudinal and lateral arms, and from theadjacent robot cells through the transmission routes 1222, 2122, 2223,2232, and generates an instruction to servo controllers 22012, 22022 soas to actuate the servo motors 2215, 2225 on the active arms in bothlateral and longitudinal directions. The servo motors 2215, 2225 rotateon the basis of this instruction and turn the gear 2213. The angle ofrotation of the servo motors 2215, 2225 are sensed by the sensors 22013,22023, and are fed back to the controller 22011. If the instructed angleof rotation is different from the actual angle of rotation of the servomotor, the controller applies a correcting angle of rotation to theservo controller.

The controller also gives the instruction as to whether the gear shouldbe kept under the free or locked state.

FIG. 9 shows the internal construction of the controller. The processor22010 of the controller exchanges the data with the adjacent robot cellsthrough the transmission routes 1222, 2122, 2232, 2223 and interfaces220111, 220112. It also gives and receives signal data with the sensor,the servo sensor and the servo motor through the interfaces220117-2201111. The data received from, or to be delivered to, theinterfaces 220111, 220113, 220115, 220117, 220119, 2201111 are stored inbuffers 1, 220113. On the other hand, the data to be received from anddelivered to, through the interfaces 220114, 220116, 220118, 2201110,2201112 are stored in buffers 2, 220114. The buffer 1 stores the datarelating to the lateral direction, and the buffer 2 does the data on thelongitudinal direction. On the basis of the data inside these buffers,the processor 220110 calculates the adjusting quantities of the lateraland longitudinal active arms, and the result of calculation is stored ineach arm file 220115, 220116. The processor 220110 controls the servomotors 2215, 2225 on the basis of the data inside these files 220115,220116.

The operation of each robot cell and the operation of robot part formedof a group of robot cells will now be described with reference to FIGS.6 through 8.

It will be assumed that the robot cells 11 through 37 are arranged inthree columns and seven rows and 17, 27 and 37 are fixed to supportpoles. These robot cells are directed (1) to encompass an object 1, (2)to grip the object 1 with a predetermined force, and (3) to move theobject 1, and the cell operate in the three steps in accordance with thestated objective of moving object. First of all, the first step will bedescribed. Assuming now that the object 1 and the robot part formed ofthe group of robot cells are spaced apart from each other as shown inFIG. 6, then each robot cell extends the lateral arm if the robot cellis out of contact the object 1. In this case, the longitudinal arm islocked and the lateral arms of the cells 21-27, 31-37 are kept free sothat the cells of each row move in parallel with one another. When thelateral arms of the robot cells 11-17 are gradually extended, the sensor22024 of the cell 11 first senses the object 1. Then, the free state ofthe lateral arm of each robot cell 11, 21, 31 is released. As the armsof the robot cells 11-17 are extended further, robot cell 11 movestowards the object 1, so that the arm between the robot cells 11 and 12keeps an angle θ relative to the longitudinal arms between the robotcells 32, 22 and 12. The robot cells 11, 21, 31 control the active armsso that the lateral arms of the adjacent robot cell pairs (11, 12), (21,22), (31, 32) of each row are parallel to one another. Therefore, therobot cell 12 which detects the change of the longitudinal/lateralnegative arm angle θ by its arm angle sensor 22015 informs those robotcells 11, 22 which have the active arms and are adjacent thereto in thelateral and longitudinal directions, of the angle θ at that time.

Upon receiving this data θ, the robot cell 22 likewise transmits thedata to the adjacent cells 21 and 32, at a scheduled time and the robotcell 32 transmits it to the cell 31 upon receiving the data θ. In thismanner, the angle θ is detected at a scheduled time and is transmittedto the adjacent robots. The robot cell 11 informs the robot cells 21 and31 of the arm length between the cells 11 and 12. The robot cells 21, 31having the active arms calculate the lateral arm lengths in accordancewith the algorithm shown in FIG. 10. As the arm length h between therobot cells 11 and 21 is known in advance, the robot cell 21, forexample, calculates the lateral arm length l (21, 22) in accordance withthe following equation on the basis of the lateral arm length h and theangle φ informed from the robot cells 12 and 11:

    l (21, 22)=l-2h cos θ                                (1)

Likewise, the robot cell 31 calculates l (31, 32) in accordance with thefollowing equation:

    l (31, 32)=l-4h cos θ                                (2)

The robot cells 21 and 31 move the servos of the lateral active arms inaccordance with this value, thereby adjusting the arm lengths. When thecells 21 and 31 adjust the arm lengths, the cell 11 does not change thearm length, while the cell 12 fixes the shaft 2216 of the arm between itand the cell 11 to prevent its rotation.

In this manner, the robot cell 11 changes the arm angle on the basis ofthe operations of the object sensors 22014, 22024 while extending thelateral arm but not separating away from the object. If the arm anglebetween the robot cells 11 and 12 changes, each robot cell 21-27, 31-37adjusts the arm in accordance with the algorithm described above.

In order to let the robot cells 12-17 smoothly entwine the object 1, thecells 12, 22, 32 on each row periodically send information on the armangle and length relative to the robot cell 11, 21, 31 to the subsequentrobot cell 13, 23, 33 on the rear row. Similarly, the cells 13, 23, 33inform the subsequent cells 14, 24, 34 of the arm angle and length atthat time. In this manner, the robot cells on the front row sendinformation on the existing arm angle and length to the subsequent cellson the rear row. As each robot cell advances and reaches the positionwhere the subsequent cell has been occupied, it adjusts the arm angleand length on the basis of the data that has already given thereto.

Incidentally, when the arm angle θ becomes small and the arm lengthbetween the adjacent robot cells 11-12 becomes small, the arm length l(31, 32) between the robot cells 31 and 32 is below the minimum armlength l_(min), that is, ##EQU1## and the robot cell 31 can not achievethe arm angle θ. In other words, since the robot 31 can not attain thearm angle θ, it comes into contact with the robot cell 32. Since suchoccurrence is possible, each robot cell controls the servo so as torealize the minimum arm length l_(min) if the calculated value of thelateral arm length is below the predetermined minimum arm lengthl_(min).

Judgement whether or not the arms entwine the object is made in thefollowing manner. If the arms are judged as entwining the object, thesecond step mentioned above is followed. FIG. 11 shows the state inwhich the arms encompass the object 1. The robot cells 12 through 19between the robot cells 11 and 19 on both ends come into contact withthe object 1, and the robot cell 20 calculates the angle of theirlateral arms on the basis of the value of the arm angle sensor 22015. Ifthe angle θ exists on the side opposite to the longitudinal arm,

θ>0

and when the angle exists on the side of the longitudinal arm,

θ<0.

In FIG. 11, therefore,

θ₅ <0

for the robot cell 16, and

θ₁, θ₂, θ₃, θ₄, θ₆, θ₇, θ₈, θ₉ >0

for the robot cells other than the cell 16. Each robot cell exchangesthis angle at a scheduled time, and calculates the sum θ of theseangles: ##EQU2##

When θ is greater than a certain predetermined angle θ, the arms arejudged as entwining the object 1.

Incidentally, in FIG. 7, it is assumed that among the tips of the groupof robot cells, only one robot cell 11 senses the object 1. However, therobot cells 11, 21, 31 might sense simultaneously the object 1 asdepicted in FIG. 12. In such a case, each robot cell of the group cannot extend the arm. In the case of FIG. 7, too, there might be the casein which the robot cell 11 does not slide on the object 1 when it comesinto contact with the object, and can not extend the arm, either. Inthis case, the robot cell 11 of the first row, for example, is arrangedin advance so as to slide along the object. Therefore, the robot cell 21contracts the longitudinal active arm by a predetermined length, andmakes free the lateral active arm of the robot cell 11. As a result, therobot cell 11 is attracted to the robot 12 as shown in FIG. 13. Next,the arm angle between the robot cells 11 and 12 is fixed, and the robotcell 21 extends the longitudinal active arm to the original length.Thereafter, the robot cells 11-17 of the first row extend their lateralactive arms and encompass the object 1.

The second step is to grip the object 1 with a predetermined level offorce when the group of the robot cells encompass the object 1. First,each robot cell stops extending the lateral arm. The robot cells 21-27and 31-37 other than those of the first row fix the arm angles in thelongitudinal and lateral directions, respectively.

Next, the robot cells 21-26 make control so as to extend the ordinatearm length between the robot cells that are in contact with the object11-16 and the robot cells 21-26. After the arms are extended in apredetermined length, control of fastening the object 1 is completed.

The third step is to move the object that has thus been gripped. Thiscan be accomplished when the robot cells on the column other than therobot cells coming into contact with the object 1 change their armlength in the same way as in the first step.

Since the robot of the present invention consists of a large number ofrobot cells, the robot does not undergo breakdown even when part of thecells are out of order. It will be assumed that the robot cell 22 of thesecond row, for example, in FIG. 7 is out of order and enters the freestate. In this case, the arm length of the robot cell 22 is primarilydetermined by the control of the arm length of the adjacent robot cells.When the robot cell 12 of the first row is out of order, thelongitudinal/lateral arm angle θ can not be measured. Accordingly, therobot cells 11, 21 and 31 keep the previous arm lengths fixed. When therobot cell 32 of the third row is out of order, no change of the controlmethod is necessary for the other robot cells. However, when any of therobot cells 11, 21, 31 of the first column is out of order, thefastening control of the second step can not be effected, so that therobot cells 12, 22, 32 of the second row make control in place of theformer.

The embodiment described above deals with the method of controlling arobot member formed by a group of robot cells when the object 1 exists,but even when the object 1 does not exist, the group of robot cells canbe operated in accordance with a predetermined pattern. This can beaccomplished by informing each robot cell of the first row, of thelateral arm length and of the arm angle so that each robot cell can makenecessary control.

As can be clearly understood from the description that has been thusgiven, the hardware and software for each robot cell are uniform, andcontrol by each robot cell is made through the communication between theadjacent robot cells. Accordingly, there is no necessity at all of thechange of the content of each robot cell even when the number of robotcells is increased or decreased.

Though the robot structure described above is a rectangular shapeconsisting of three rows, a robot construction consisting of four ormore rows or a construction having a hexagonal shape can be similarlyrealized.

The arm control of each robot cell may be made by methods other than themethod described above.

The present invention makes it possible to constitute a robot by merelycombining a plurality of autonomous robot cells having the samefunction, and to change the number of robot cells to be combined inaccordance with an intended object. The hardware and software of theother robot cells need not be changed at all even when the combinationof the robot cells or particular robot cells are expanded or diminshed.Moreover, the robot as a whole does not undergo breakdown even when oneor more of these robot cells are out of order, but can keep thepredetermined function. Since a large number of robot cells can be used,the freedom of the operation of the robot as a whole can be increased inproportion to the number of interconnected robot cells employed. Sinceeach robot cell operates independently, the response of the robot as awhole can be improved.

What is claimed is:
 1. A cellular type robot apparatus having a cellulartype component part consisting of a plurality of intercoupled robotcells, said component part being capable of controlling its shapethrough coordinate but independent movements by said robot cells; andaninformation transmission medium connecting each of said robot cells toother robot cells; each of said robot cells including means for sendingto other robot cells on said transmission medium information related toan operating status of said component part and means for independentlydetermining and controlling the movements of its robot cell based oninformation received from said transmission medium, and at least onerobot cell including means for detecting an operating status of saidcomponent part.
 2. The cellular type robot apparatus as defined in claim1 in which all of said robot cells are uniformly configured.
 3. Thecellular type robot apparatus as defined in claim 1 in which each ofsaid cells includes means for detecting its own operating status.
 4. Thecellular type robot apparatus as defined in claim 1, further includingmeans for exchanging information between a plurality of said robotcells, and means connected to said exchanging means for setting theobject of action of said robot cells as a group.
 5. The cellular typerobot apparatus as defined in claim 1 wherein a plurality of said robotcells are connected in a building block arrangement by combination meanscapable of increasing and decreasing a parameter of the configurationformed by said robot cells.
 6. The cellular type robot apparatus asdefined in claim 1 wherein each of said robot cells includes combinationmeans capable of changing the configuration of said component part withthe other of said robot cells in response to the object of action. 7.The cellular type apparatus as defined in claim 5 wherein saidcombination means capable of changing the combined state is at least onearm of variable length.
 8. The cellular type robot apparatus as definedin claim 7 wherein said combination means includes two sets oflongitudinal and lateral arms.
 9. The cellular type robot apparatus asdefined in claim 6 wherein each of said robot cells further includesmeans for sensing the existence of an object in proximity thereto, meansfor sensing contact with said object, and a plurality of said robotcells including means to control the operations of said cells so as tocome into contact with said object.
 10. The cellular type robotapparatus as defined in claim 9 wherein said robot cells coming intocontact with said object operate conjointly to grasp said object. 11.The cellular type robot apparatus as defined in claim 9 wherein each ofsaid robot cells slides on said object upon coming into contacttherewith allowing adjacent robot cells to come into contact with saidobject.
 12. The cellular type robot apparatus as defined in claim 1which further includes means for releasing the operating state of any ofsaid robot cells which is out of order, and for letting robot cellsadjacent to said robot cell which is out of order replace the operationof said out of order robot cell.
 13. A robot apparatus comprising atleast one group of interconnected robot cells which combine to provide acomponent part of variable configuration including means for setting theobject of operation of said group of robot cells, wherein each of saidrobot cells includes:an information transmission medium connecting eachcell to said other cells; means for sending to other robot cells aninformation on said transmission medium related to the status of saidcomponent part; and means for independently deciding its own actionbased on information received from said transmission medium.
 14. Acellular type robot apparatus comprising:a plurality of robot cellsphysically coupled to one another to form a single manipulative member;and an information transmission medium connected between said robotcells for carrying information to and from said cells from and to othercells; each of said robot cells including: first means for detecting theoperating condition of the robot cell; second means for detecting theoperating condition of other robot cells; and third means forcontrolling the operation of the robot cell on the basis of informationprovided by said first and second means.
 15. A cellular type robotapparatus according to claim 14, wherein each robot cell is connected toat least one other robot cell by way of an arm of controllably variablelength.
 16. A cellular type robot apparatus according to claim 15,wherein a plurality of robot cells have a pair of lateral arms and apair of longitudinal arms by which they are connected to adjacent robotcells, the length of said arms being controlled by said third means.